A valve amplifier against a solid-state one. They are not really rivals: they differ in character, in what they will drive and in what owning them involves, so start there rather than with the watts.
| Area | Better | Why |
|---|
| Power | B | Rega Elex-R has more power - 72W against 35W into 8 ohms. That is about 3.1dB, so it plays usefully louder before it runs out and has more in hand on peaks. |
| Room size | depends | We rate Cayin Jazz 70 the better fit for desk or near-field listening and a small room, and Rega Elex-R for a mid-size room, a large room and a very large room. Match the amplifier to the room you actually have, not the one you want. |
| Built-in DAC | A | Cayin Jazz 70 has a DAC on board; the other needs an external one, which is another box, another power lead and another purchase. |
| Analogue inputs | B | Rega Elex-R takes more analogue sources - 4 against 3. |
| Phono stage | depends | Rega Elex-R has a built-in phono stage (MM) and Cayin Jazz 70 does not. Decisive if you own a turntable, completely irrelevant if you do not - and an outboard phono stage is easy to add later either way. |
| Amplifier type | depends | Cayin Jazz 70 is Tube and Rega Elex-R is Solid State. Valve designs are usually warmer and softer at the limits and need their tubes replaced eventually; solid state is the lower-maintenance choice. This is a taste and ownership decision, not a quality one. |
| Shelf space | depends | Cayin Jazz 70 takes up about 26% less shelf area (1014cm² against 1376cm²). |
| Price | evenly matched | Priced within a few per cent of each other. |
| Watts per dollar | B | Rega Elex-R is the cheaper watt - about $19 per watt against $40. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Cayin Jazz 70 B Rega Elex-R
depends neither is better in the abstract - it turns on your room, your system or how you will use them. Only specs published for both amplifiers are judged; anything missing on either side is left out rather than guessed.
Which should you choose?
Rega Elex-R has the edge on paper, though not by much. The rows marked "depends" are more likely to decide this than the score is. Start with the room. In a large or open-plan room, or with speakers that are hard to drive - low sensitivity, or an impedance that dips - Rega Elex-R has the headroom, and headroom is what stops an amplifier hardening up on peaks. At desk distance or in a small room, 35 watts is already more than most people ever use, and the extra 37 watts would be headroom you pay for and never hear - we rate Rega Elex-R poorly for near-field use for exactly that reason. If you play records, Rega Elex-R saves you buying a phono stage; if you do not, ignore that row entirely.
What a spec sheet cannot show: how either sounds with your speakers, how the controls feel day to day, and what the app is like to live with - which is where most all-in-one amplifiers are actually won or lost. Power figures are the manufacturers' own and are not measured to a common standard, so treat small differences as noise. If you can hear both, that will tell you more than any row above.